The present invention relates generally to multiple speed transmissions and is more particularly concerned with multiple output geared transmissions.
In view of the extensive and rapid depletion of existing crude oil reserves there has developed an intensive search for new sources of oil. Extensive exploration has led to the discovery of potentially valuable oil bearing formations in such remote areas as Alaska and Peru. Interestingly, despite the disparate geographic and climatic differences attendant these finds, many of the requirements for drill rigs suitable for exploratory and production drilling in such unpopulated wilderness areas are quite similar. One such requirement is that the drill rig be capable of disassembly into components of sufficiently small size and weight as to be susceptible of movement to and from the drill site by means of helicopter transportation. Too, also arising as a result of the primitive conditions attendant these remote well sites, it is further important that the design of the drill rigs be such that they are simple and easy to service.
One of the factors which has, heretofore, mitigated against the provision of suitable drill rigs for remote locations has resided in the inability to perform a sufficiently light-weight disassemblable power group to service the drill rig, one of the difficulties being that the prime movers conventional in the art are usually available only with transmissions which are integral therewith. Such conventional power group designs, while convenient where site access and rig maintenance pose few problems, are not generally acceptable for operations in remote areas since such integrated prime mover/transmission assemblies are generally excessively heavy for helicopter transportation thereof and are complex and difficult to service.
In accordance with the present invention, however, these problems have been substantially ameliorated.